Global Patent Index - EP 0826632 B1

EP 0826632 B1 20000510 - Process for making basic sodium and/or potassium aluminum sulphates and for making paper with such

Title (en)

Process for making basic sodium and/or potassium aluminum sulphates and for making paper with such

Title (de)

Verfahren zur Herstellung von basischen Natrium-und/oder-Kalium-Aluminiumsulfaten und Verfahren zur Herstellung von Papier mit diesen Stoffen

Title (fr)

Procédé de préparation de sulfates d'aluminium et de potassium et/ou de sodium et procédé de préparation de papier avec ceux-ci

Publication

EP 0826632 B1 (EN)

Application

EP 97114825 A

Priority

US 70388396 A

Abstract (en)

[origin: US5865952A] A process in which a leach liquor of Al2(SO4)3+K2SO4+Fe2SO4 and other sulphates is introduced to a surface-cooled crystallizer that drops the Al2(SO4)3+18H2O. The leach liquor is pumped through a heat exchanger that keeps a temperature of 160 DEG F. and the surface temperature of the surface-cooled crystallizer is maintained at 60 DEG F. The temperature gradient within the leach liquor promotes crystal formation. These crystals are then supplied to mixture which includes K2SO4 in a simple crystallization and evaporation step that uses a vacuum of twenty inches of mercury and heat to drop Al2(SO4)3+K2SO4+24H2O. A pressure of 250 PSI and a temperature of 200 DEG C. are then applied in a discrete continuous process that yield a basic sodium or potassium aluminum sulphate and excess sodium sulphate or potassium. The excess sodium sulphate or potassium sulphate is returned to the simple crystallization and evaporation step. The basic sodium aluminum sulphate comprises particles that are at least forty percent below two micron. This is then applied to a delaminator that converts eighty-five percent of the particles to under two micron. The BKAS and/or BNaAS is used as a filler in the making of paper.

IPC 1-7

C01F 7/76

IPC 8 full level

C01F 7/76 (2006.01); D21H 11/00 (2006.01); D21H 17/63 (2006.01); D21H 17/67 (2006.01)

CPC (source: EP)

C01F 7/762 (2013.01); D21H 17/67 (2013.01); C01P 2004/61 (2013.01)

Designated contracting state (EPC)

DE FI NL

DOCDB simple family (publication)

US 5865952 A 19990202; CA 2213926 A1 19980227; DE 69701937 D1 20000615; DE 69701937 T2 20001228; EP 0826632 A1 19980304; EP 0826632 B1 20000510; JP 2003113591 A 20030418; JP 3370570 B2 20030127; JP H10101330 A 19980421; US 5783163 A 19980721

DOCDB simple family (application)

US 7463098 A 19980507; CA 2213926 A 19970826; DE 69701937 A 19970827; DE 69701937 T 19970827; EP 97114825 A 19970827; JP 2002210603 A 20020719; JP 22997097 A 19970826; US 70388396 A 19960827